Tag Archives: flippers

In Williams pinball machines of this vintage, the flippers are driven by the solid-state Fliptronics II board, which is located in the backbox in the upper left. There are 4 fuses, one for each possible flipper in the game: upper right, upper left, lower right, lower left (F901 – F904 respectively, each of which are 3 amp, slow-blow). In the case of many Williams machines, there are less than 4 flippers. If your game only has two flippers, you have 2 spare fuses available if you’re in a pinch.

In the case of Indiana Jones, there are only 2 flippers. When I was first contacted by the customer, I told him to check F904 which is labeled for the lower left flipper. He went ahead and replaced it, but it didn’t solve the problem. So, I paid the machine a visit.

I determined that the flippers in this machine are wired to the upper flipper outputs, therefore F902 was the culprit. I vaguely recall running into this somewhere else. Maybe that’s why it’s called The Pinball Adventure.

So, if you have a Fliptronics machine and you have a non-working flipper, check both upper and lower fuses. By the way, the fuses are arranged on the circuit board in the same way the flippers are arranged on the playfield: upper left fuse is the upper left flipper, etc.

The owner previously knew the lower right flipper coil was bad, so I had a replacement on hand when I arrived. After replacing the coil, I checked all of the fuses on the Fliptronics board and found one blown and another fuse as the wrong value. All four fuses should be 3 amp slo-blo (MDL type).

I powered up the machine and found that the flipper was often sticking in the up position. Before the coil went bad, this was one of the original complaints. It wasn’t a mechanical sticking, but the hold coil was staying energized when it should have released. I tracked the problem down to the flipper opto board. The bottom edge of the board wasn’t was tightened down all of the way. The board was just twisting enough that it would move slightly when the flipper button was pressed, then it didn’t detect the button being released until some vibration in the machine caused the board to move a little. I tightened the mounting screws and that problem was solved.

The upper right flipper was kicking but not holding. It looked like all of the wires were connected to the coil and the terminals were wrapped in electrical tape. So I looked at the Fliptronics board and checked the voltages coming back from the flippers. When the game is powered up, in play mode, and flippers is NOT energized, 70 volts should be present on every terminal of J902 that has a wire connected to it (it varies from game to game based on the number of flippers). This is a good way to check coils and connections. In this case, there was no voltage present on pin 4. That verified that there was an open connection in the coil or the wiring.

So I went back to the coil for a closer look. I unwrapped the tape and found that the terminal strip on the end of the coil bobbin, where the connections are made, was broken. It was the reason why it had been taped. The fine gauge wire used in the winding of the hold circuit had broken inside the coil. Some coils can be repaired if the broken wire is on the outside layers of the coil, but in this case it wasn’t.

I generally don’t stock flipper coils, so I would have needed to order it. The owner elected to buy a new coil at the Pinball Showdown, which is happening this weekend in Denver.

Not all flipper coils are created equal for the Williams pinball machines. Each pinball machine was designed to use specific coils based on what the coil needed to accomplish in each game layout.

FL-11753 Yellow – Used with short flippers and close shots

FL-11722 Green – Used for close shots near drop targets

FL-11630 Red – The standard, most commonly used coil

FL-15411 Orange – Used for long playfield shots

FL-11629 Blue – Used for long shots and high ramps

In the case of White Water, the blue coil is specified as the lower right and the red coil is specified for the upper right.

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"Randy is a true professional with amazing knowledge of electrical wiring, programming, boards and mechanical workings. He has always arrived promptly with all the tools and parts needed to efficiently complete the jobs. Randy has worked on my three Williams machines (Taxi, T2, and Funhouse) and based on his previous work, I am confident he could solve any future issue." --Greg M., Louisville, CO

"Randy was there an hour and found the problem and also a couple other potential issues. He was very professional and knowledgeable and I feel he has the ability to troubleshoot anything pinball or anything electronic for that matter." --Craig H., Broomfield, CO

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